Process of converting crude iron into malleable iron or steel



(No Model.)

J. W. BOOKWALTER. 11G 01111115 111011 111170 111111111113111: 111011 01b S1111# PROCESS 0F CONVERTI linien "retiree prirent' Ottica..

PROCESS OF COliVERTlNG CRUDE lRON lNTO MALLEABLE IRON (lll STEEL.

l SPECIFICATIN forming part of Letters Patent No. 411,419, dated September 24, 1839.

Application filed November 2B, 188B. Serial llo. 292,136. (No model.)

To CLZZ w/Lom l 77mg/ concern.:

Be it known that I, JoHN W. BooiiwALruR,

a citizen ot the United States, residing at Springfield, Clark county, State of Ohio, have 5 inyenteda new and useful Improvement in the Process of .Converting Crude Iron into Malleablc Iron or Steel, of which the following is a full,clear, and exact speoiiieation.

`In .the conversion of crude ironfnto inalieio able iron or steel by what-is known a's'lfhe Roberts process, in which the body of in etal in the converter is acted upon by a blasttln'itstrips oft from the body `of metal and Ilinely divides small portions thereof at one time, while impartinga gyratory motion to the main body that feeds every portion in vsuccession into position to be acted upon by `the blast, there are certain variable conditions which vary the ultimate results unless provision is made to counteract them. Thus when the molten metal is placed in the converter it is much cooler and therefore .more viscid or less fluid than it afterward becomes, as during the process of conversion its `temperature is in- 3o where the air-blasts are applied at or `near the surface ot' `the bath, as in the Roberts` process, the extent to which theoxygeninthe y blast is brought .into contact and combines with the combustible elements of the iron is l dependent to a great degree upon the rapid ity of the circulationof the. metal `brought-about by the mechanical action ofthe air upon the mass vof the metal.

In proportion as the metal' iirst placed in'` the converter is cooler and more yiscid a blast of greater lforce must be applied to ovcrcomethe `inertiao'l `the metal and set it in motion'andlimpart and `maintain the reuui- 1 site speed ol the gyratory, motion. It thcreyfore t'ollowsthat `the `amountot `pressare ot air admitted atthe preliminarystate ol' conversion that will-impart the 'proper circulation to the metal would be vtoo,trreatwhen the liquid 4fbctnnncs `nuire. liquid and ,the `part-leica aremore mobile und yield more readily tu creased. 'lhisincreasing,temperature nesult-s l the applied force, because in that condition the blast will tend to produce a too rapid motion to the metal and act too 1violelitly upon the same. 'lhis variation'in the degree ot the fluidity and mobility oi the metal at 'diltereut stages of the process of conversion can lio-compensated for with partial success by gradually diminishing the quantity ofthe air and the pressure of the blast as the fluidity of ihe'metal increases, or by yaryiug tl1ean- 6o gle at `which the air is forced upon the metal, but it is the object of my intention to provide more complete means for securing this result by maintaining- .more constant and throughoutthc whole period ot' the same than can be done by varying the quantity of vair and pressure or the angle of the blast.

In carrying out my invention I make use of an apparatusot' any suitable constructiong as, [or iuslance, sin-l1 an apparatuses is illustrated in the accompanying drawings, in which- Figure l is an cle.\"at'.on in section of a corr used in'earrying out my invention. Fig.' 2 is a sectional plan on the line 2 3, Figi.

'lhe charge is introduced into the converter A., as usual, and in order to produce at the beginning of ,the act-.of conversion, when the 8o metal is in a more viscid siate, a `snllicient rapid circulation of ythe entire body of metal tobring'thc combustible elements held by the iron within the `sphere of the oxidizing influence of; thc atmosphere passing `through 85 the tuyeres win the toi-m of a blast, as inthe Roberts process, I at the beginning employ a blaat of maximum volume and pressure, which will lnoon oyercome the inertia of the metal and quickly impant the desired speed 9c of `gyration `and rapidly .bring the combustible elements yheld by the iron into position to be subjected `lo the'oxidizing yinfluence of the air, Ithus avoiding the uiendem-yto oxforconwersion, `whiff' `would `result if the metal 95 cireulaiedbut slowly and a strong blast conlinuouslyimpingged Vupon u limited portionof I :the `aurizuieol the metal.

j inox-der iollurther reduce the danger of fixed relations iurV the act of conversion verter of the Roberts-type which could be 13 `overoxuliaiug .the `metal at any singe of lthe 10o i thoroughly consume Thus a portion of the oxygen maybe burned "Without necessarily supplying to the metal at process, but without'interfering with the desired mechanical etleet et the blast; l vary the proportion ot' the oxidizing agent in any suitable way-'as, for instance, by reducing lthe amount ot' oxygen contained inthe blast.`

any stage during the conversion a larger quantity of oxygen than is necessary to the eomlmst-ible elementspresented to it by t he circulation of the metal.

'lhc deoxygenizing of theair willvary with the varying conditions of the metal. lhus it is effected to the maximum extent at the be` ginning of the process and is contzimlednntil the metal acquires the requisite gyratory motion, and is then varied throughout; the process of conversion to meet thc requi'renumls growing out of the reduction in the quantity ot' carbon, silicon, and other combustible el ments held by the iron. As the eonvm'sion proceeds the quantity and the pressure ot' the air arereduccd inproportion tothe increase iu the fluidity of the metal, so as to avoid ahy tendency to produce too rapid a circulation or too violent anaetion upon the metal in the bath, which would result in returning-the iin-1 purities generated in the process ot' eonve"- sion to and mixing them with the body of the metal. lly keeping up the volume and pressure of the air at the beginning of the operation to a point to suit the less` mobile character of the metal'when first. put intothe converter, and b v reducing the quantity ol' oxygen contained in the blast, and thus avoiding the danger of crei-oxidizing the metal, and afterwards by reducing the "0lume and pressure ot' lthe air to suit the iucreased -mobility that results from agreat'er fluidity of the metal, and by further reducing the quantityot oxygen contained in the air in proportion to the reduetionof thequan'tity of carbon and silieon and lother combustible elements to be burned out as the process ot.' conversion proceeds, l am enabled to maintain throughout the whole period of` couversion a more perfect relation of the essential conditions necessary toa thorough and eomplete couver-simi of the metal. than would be possible if a tixed vol ume and pressurcof air with its full proportion of ogygen was admitted throughout the whole process ol" conversion, or even by the use of a variable quantity and pressure ot' air admitted withouty Varying the lwoportion of oxygen contained in theair.

l claiml 'lhe wit-hiin-described improvement in the process ot' converting crude iron into malleable irou or steel by a blast acting upon partI of a body ol' metal to impart a gyration thereto and strip therefrom limited portions in succession, the said improvement consist.- ilg in diminishingl the pro/portion ol' oxygen in the blast and in also varyingl the quantity and pressure ot' the blast during the process ol conversion, substantially as and i'or the purpose set forth.

lu testimolly-whereof I have'sigued my'ualne tothis specification inthe presenee of -two subscribing witnesses.

JOHN W. I lOOl(UH/FER.

Wit nesses:

lm'rn J. (hnswolin, H. (l. (JoNNolc. 

